PECAM1 and neoplasm: Immunohistochemistry (IHC) results showed that CD34 (5/5) was the most frequently positive in these cases, followed by erythroblast-specific transformation-related genes (ERG) (4/5), CD31 (4/5), factor VIII (4/5), and vimentin (3/5), while all tumor cells negatively expressed transcription factor E3 (TFE3).